-- Copyright (C) 2018-2021 by KittenOS NEO contributors
--
-- Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted.
--
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
-- THIS SOFTWARE.

local fmt
fmt = {
 pad = function (t, len, centre, cut, ra)
  local l = unicode.len(t)
  local add = len - l
  if add > 0 then
   if centre then
    t = (" "):rep(math.floor(add / 2)) .. t .. (" "):rep(math.ceil(add / 2))
   else
    t = t .. (" "):rep(add)
   end
  end
  if cut then
   local i = 0
   if ra then
    i = -math.min(0, add)
   end
   t = unicode.sub(t, i + 1, len + i)
  end
  return t
 end,
 -- Expects safeTextFormat'd input
 fmtText = function (text, w)
  local nl = text:find("\n")
  if nl then
   local base = text:sub(1, nl - 1)
   local ext = text:sub(nl + 1)
   local baseT = fmt.fmtText(base, w)
   local extT = fmt.fmtText(ext, w)
   for _, v in ipairs(extT) do
    table.insert(baseT, v)
   end
   return baseT
  end
  if unicode.len(text) > w then
   local lastSpace
   for i = 1, w do
    if unicode.sub(text, i, i) == " " then
     -- Check this isn't an inserted space (unicode safe text format)
     local ok = true
     if i > 1 then
      if unicode.charWidth(unicode.sub(text, i - 1, i - 1)) ~= 1 then
       ok = false
      end
     end
     if ok then
      lastSpace = i
     end
    end
   end
   local baseText, extText
   if not lastSpace then
    -- Break at a 1-earlier boundary 
    local wEffect = w
    if unicode.charWidth(unicode.sub(text, w, w)) ~= 1 then
     -- Guaranteed to be safe, so
     wEffect = wEffect - 1
    end
    baseText = unicode.sub(text, 1, wEffect)
    extText = unicode.sub(text, wEffect + 1)
   else
    baseText = unicode.sub(text, 1, lastSpace - 1)
    extText = unicode.sub(text, lastSpace + 1) 
   end
   local full = fmt.fmtText(extText, w)
   table.insert(full, 1, fmt.pad(baseText, w))
   return full
  end
  return {fmt.pad(text, w)}
 end
}
return fmt